DJ : Short for dust jacket, a protective and often decorative wrapper, usually made of paper which wraps around the binding of a book.

vg : Very Good condition. can describe a used book that does show some small signs of wear - but no tears - on either binding or paper. Any defects must be noted. (defined by AB Bookman's Weekly)

xlib : An abbreviation for ex-library, a former library book, generally containing library acquisition and ownership stamped markings, and other typical indications of the library's use.